As disclosed in British Pat. No. 1,324,687 and European patent application No. 22587 (published Jan. 21, 1981), certain 1-aryl derivatives of 3-amino-2-pyrazoline such as 1-phenyl-3-amino-2-pyrazoline, are known to have anti-inflammatory activity. U.S. Pat. No. 3,927,025 discloses that certain 1-aralkyl (e.g., 1-benzyl) derivatives of 3-amino-2-pyrazoline have anti-spasmodic activity in mammals.